Process for dyeing fabric



Patented Sept. 7, 1943 raoonss Foa DYEING FABRIC Otto' Grimm andHansRauch, Darmstadt. Germany, assignors to Riihm & Haas Company,

Philadelphia, Pa.

No Drawing. Application August 22, 1939, Serial No. 291,327. In GermanyAugust 23, 1938 10 Claims.

This invention relates to materials of high molecularweight containingnitrogen and to the process ofpreparing them. It relates moreparticularly to products obtained by the interaction of a water-solublepolymeric amide, an aldehyde and an amine. It also relates to the use ofthe products thus obtained in fixing dyes on fabrics, particularly aciddyes on cellulosic fabrics. It further relates to the use of theseproducts in dyeing leather and also in the filling of leather.

Theproducts formed by the interaction of a polymeric amide such aspolymethacrylic amide, an amine such as dimethylamine, and an aidehydesuch as formaldehyde are all high molecular weight substances containingnitrogen. They are soluble in water and form with acid dyes and withnatural, synthetic and mineral tanning agents, compounds which areinsoluble in neutral and acid aqueous solutions. On account of theseproperties the new products are useful in dyeing fabrics, particularlycellulosic fabrics, and leather. They are also useful in the process oftanning because the insoluble products which they form with the tanningagents can be easily formed within the leather, thus yielding a good,full leather.

It is known that cellulosic fabrics cannot be dyed directly with aciddyes. Many methods have been proposed for treating fabrics or fibers ofthis kind with basic substances so as to introduce basic groups into thecellulose molecule. This is important because very often it is desirableto weave fabrics from two or more fibers,

for example cotton and silk. Such fabrics cannot be dyed with a singledye to a uniform color. If basic groups are added to the cellulosemolecule, then acid dyes can be used on mixed fabrics and uniform colorobtained. Processes for treating cellulose so as to introduce suchgroups include treatment with ethylene imine, epichlorhydrine followedby ammonia, impregnation with urea-formaldehyde condensation products,etc. These all have the disadvantage that the fabric must be subjectedto a separate treatment to prepare it for dyeing with acid dyes. Whenusing the products of the present invention for the purpose of fixingacid dyes on cellulosic fabrics, it is only necessary to impregnate thefabric with a solution of the condensation product and then treat thefabric with a solution of an acid dye. By means of this treatment thedye .2 bound in the fiber. In some cases very unifonn dyeings can beachieved by first impregnating the fabric, either hot or cold, with theproducts of this invention, wringing out, drying at a temperature of 40to 50 C., and then applying the dye. In many cases it is advantageous todry the impregnated fabric at higher temperatures, for example about C.before dyeing.

When dyeing fabrics, leather or other fibrous material, the dye may beapplied first, followed by treatment with the high molecular weightnitrogenous products for the purpose of fixing the dye on the fiber. Thelightfastness of such dyeings is much better than when the treatmentwith the new products is omitted.

When used for filling leather, the new con densation products have manyadvantages over the usual fillers such as kaolin, calcium carbonate,etc. These are usually drummed into the leather along with the fatliquor. The new products on the other hand may be added before the fatliquor and, since they form insoluble V products with the tanning agent,the actual filling material is formed directly in the leather.

'A single treatment of the leather with these mamedium. It ispreferable, however, to carry out the reaction in a slightly acid mediumin which case the amine is employed in the form of one of its salts. V

The amines which can be used in preparing these condensation productsare those which have at least one hydrogen atom attached to the aminonitrogen atom. Examples of such amines are monomethylamine,dimethylamine, the primary and secondary ethyl, propyl, butyl and higheraliphatic amines, carbocyclic amines such as benzylamine,cyclohexylamine, naphthylamines, phenylenediamines, and heterocyclicamines, such as piperidine. When these compounds are insoluble ordifficultly soluble in water they are used in the form of their salts,for example, the hydrochlorides. Other compounds containing an -NH2- or-NH-- group, for example, amino acids, may also be used in the reaction.

Formaldehydeis preferred for condensing with the polymeric amide and thealiphatic amine or amino acids. It may, however, be replaced by otheraldehydes such as iurfurol, acrolein, acetaldehyde, crotonaldehyde, etc.These aldehydes are advantageously employed in place of formaldehyde incases where the latter forms insoluble compounds with the amine, as forexample with phenylenediamine hydrochloride or p-naphthylaminehydrochloride.

The polymeric amides are those obtained by polymerimng such compounds asmethacrylic amide, acrylic amide, and other similar, unsaturated acidamides. Polymethacrylic amide is particularly suitable. It is preferableto employ polymers which yield aqueous solutions of low to intermediateviscosity because, if solutions of high viscosity are employed,difliculties in handling may arise. Joint polymers of the unsaturatedacid amides and otherpolymerizable materials such as acrylic,methacrylic and vinyl esters may be employed, in which case care shouldbe taken that the joint polymer contains a sufficient proportion ofamido groups to render it soluble in water: tained by the partialalkaline hydrolysis of polymeric acid nitriles, such as polyacrylicnitrile may also be used provided they contain a sufficient proportionof amido groups. Such compounds probably contain unchanged nitrilegroups as well as some carboxyl groups. Such compounds may be consideredto be joint polymers of acrylic amide and acrylic acid. They are usefulin the present invention but are not so efiective as polymers containinga larger proportion of amido groups. The relative amounts of thereactants can be varied as it is not always necessary to use them inexactly equivalent amounts. However, the amount of aldehyde chosenshould be such that there is not much excess, which can be detected bythe odor, in the final solution.

Both organic and inorganic acids may be used to establish the desiredhydrogen ion concentration in the reaction mass. Of the inorganic acidsthose of intermediate strength are preferable, particularly sulfuric,phosphoric, metaphosphoric, pyrophosphoric, and other polyphosphoricacids. When such acids are employed, the pH of the aqueous solution inwhich the reaction takes place should be adjusted to about 4. Theorganic acids are preferably the aliphatic caboxylic acids and may bemonobasic or polybasic. They may also contain hydroxyl groups. Examplesof such acids are formic, acetic, propionic, butyric, oxalic, lactic andtartaric acids.

When organic acids are used, the solution in which the reaction takesplace should be less strongly acid than when the inorganic acids areemployed. A pH of 6 to 6.5 is desirable for the organic acids.

reaction mixture ofthe other two, dissolves more readily in the presenceof a weak acid. The

process may also be carried 'out in the presence of strong acids and theproducts so obtained are particularly suitable for fixing tanningmaterials.

The order in which the reactants are mixed m'ay be varied. For example,the amine may first be neutralized and the solution made slightly acid,after which the aldehyde is added and "then the polymeric amide. Ifdesired, the poly- Water-soluble materials obmeric amide may be added tothe amine solution followed by the aldehyde. The amine and the aldehydemay be reacted in the absence of acid and the polymeric amide added tothe product. In this case the reaction product of amine and aldehyde maybe acidified before the addition of the amide. The polymeric amide maybe reacted with the aldehyde and the amine reacted with this productwith or without the addition of acid.

The nitrogenous condensation products made according to the inventionmay be used, as pointed out above, for filling leather because theyreact not only with vegetable tans but also with those prepared fromsulfite cellulose extracts, synthetic and mineral tans. Because of thefact that the new products are universal precipitants for all of thesetanning agents they have many advantages over precipitants previouslyused, such as glue. Glue has the disadvantage when used for this purposethat, whereas it precipitates the vegetable tans, it does notprecipitate all synthetic tans, unless these have been treated in someway to yield insoluble products with the glue. The precipitation of somesynthetic tans by glue can be prevented by the presence of sulfitecellulose tans. This is understandable because the sulfite celluloseextracts are never precipitated by glue.

For precipitating tanning agents with theproducts made according to theinvention, the pH of the solution may vary from 4.0 to 7.3 but ispreferably adjusted to about 5.5. This range is practically the same asis used in preparing the products so that in many cases the solution inwhich the reactions are carried out may be employed without furthertreatment. When products which have been made in the absence of acid areto be used as precipitants, sufiicient acid should be added before orduring precipitation so as to adjust the solution to the proper pH.

The precipitates formed from the new products and tanning agents aresoluble in alkaline solutions, for example in ammonia, but arereprecipltated when these solutions are acidified. When using theproducts to precipitate sulfite cellulose tans about equal parts byweight of the two reagents are used calculated on the dry material.

Generally speaking, the precipitants should be used at concentrations ofless than 10%, preferably about 4%, for the fixation of tanning agentsin leather because, it higher concentrations are used, there is dangerof the leather becoming tacky.

When used as a mordant for dyeing leather, textiles, etc., the newproducts result in a fuller coloring and a fixation of the dye on thesurface.

The new products thus have a wide field of application. They may, as hasbeen indicated above, be used to precipitate certain materials on animalfibers. They may also be used for the same purpose on other fibrousmaterials, such as paper and textiles.v The presence of fiber is notessential. Soluble dyes may, for example, be precipitated from theirsolutions thus yielding colored pigments and tanning agents orpolymethacrylic amide may be precipitated in the form of an adherentmass, the adhesive properties of which may be varied or eliminated bysuitable changes in its composition.

The following examples will illustrate the invention which, however, isnot limited to the exact reagents and conditions oi? reaction given asit may be otherwise practiced within the scope of the appended claims.

, Example 1 45 parts by weight of commercial dimethylamine sulfatesolution containing about 30% dimethylamine having a pH of about 4 ismixed.

with 20 parts by weight of 30% aqueous formal- '400 cc. of water. Theresulting precipitate is filtered and dissolved in 40 cc. of 2.5%ammonia. Any undissolved material is filtered. The clear solution may beused. for filling leather. By making slightly acid the material isreprecipitated and is fixed in the leather in an insoluble condition.

The ammoniacal solution may also be used for impregnating textile,paper, artificial leather, etc. In place of ammonia, other alkalinecompounds may be used, for example, sodium hydroxide or dimethylamine.

, Example 2 50 g. of dimethylarnine solution is mixed with 80 g. of 96%acetic acid giving a solution having a pH of about 6. To this solution25 g.

of 30% formaldehyde is added and the solution heated. To this there isadded, in portions, 100 g. of a 10% aqueous solution of polymethacrylicamide. Before the addition of a further portion the precipitate whichforms must be re-dissolved by boiling. The product thus obtained has apH value of about 5.2.

The solution may be used as an assistant in dyeing; for example,chrome-tanned leather is neutralized as usual and mordanted with one percent, of the above solution calculated on the shaved weight. It is thendyed with an acid or substantive dye. The resulting color is much fullerthan without the mordant.

Example 3 125 g. of ortho-phosphoric acid (tech. cone.) is added slowlyto 300 g. of-35% dimethylamine. The solution is heated and 300 cc. of30% formaldehyde added. 000 g. of 10% aqueous solution ofpolymethacrylic amide is added, in portions, to the-hot solution. Beforethe additionof any portion the precipitate formed from the previous onemust be re-dissolved .by boiling. The resulting solution may be used forfilling leather tanned with. synthetic tans, e. g., condensationproducts of phenolor cresolsulfonic acid with formaldehyde, condensationproducts of the sulfonic acids of naphthalene and its homologues withformaldehyde, phenol-aldehyde condensation products, condensationproducts of phenolsulfonic acid, urea and aldehyde, ligninsulfonic acidcontaining condensation products of phenolor naphthalenesulfonic acidand formaldehyde.

Example 22 parts by weight of 30% aqueous formaldehyde solution is addedto parts by weight ofdimethyla-mine sulfate solution containing about30% dimethylamine. The resulting solution has a pH of about 4. Thissolution is boiled and 110 parts of a 10% aqueous solution ofpolymethacrylic amide added in portions. The resulting solution may beused for filling chrome leather. This can be carried out as follows:

The skins after the usual pickling are pretanned with 80% of water, 2%of salt, and 3% of chrome alum calculated on the weight of the skins.The skins are then drummed in a fresh bath consisting of 10% of theabove solution and 20% of water. After an hour the skins are tanned inthe usual way with a basic chromium tanning material. This processyields a chromeleather with a full feel and a firm grained flank.

Eaample 5 45 g. of 30% formaldehyde is added to 90 g. of 35% aqueousdimethylamine solution. To this solution there is added while heating180 g. of a 10% aqueous solution of polymethacrylic amide in portions.Before each addition the precipitate resulting from the previousaddition must be dissolved by boiling. This solution is acidified by theaddition of 144' cc. of 96% acetic acid and may then be used for fixingtanning materials or as an assistant in dyeing.

Example 6 0.21 part by weight of a 2.5% aqueous solution of furfurol isstirred into 5.3 parts by weight of a 3.3% aqueous solution ofphenylenediaminehydrochloride. There is added while stirring one part byweight of a 10% solution of polymethacrylic amide. After heating forsome time a good precipitating agent for tanning material is obtained.

The furfurol may be replaced by crotonaldehyde, acetaldehyde orallylaldehyde.

Example 7 0.5 part by weight of of ortho-phosphoric acid is stirred with5.3 parts by weight of a 3.3%

aqueous solution of ,B-naphthylamine drochlo-.

ride and the resulting mash of crystals is dissolved by heating, 0.5part of a 2.5% aqueous solution of furfurol is added to the clearsolution whilst stirring, followed by one part of a 10% solution ofpolymethacrylic amide. After heating for some time a product is obtainedwhich can be used for fixing acid dyes and tanning materials containingacid groups- Example 8 0.05 part by weight of acroleine is first stirredwith 5.3 parts by weight of 3.3% aqueous solution ofp-naphthylaminehydrochloride. 0.5 part by weight of 85% orthophosphoricacid and then 1 part by weight of a 'l0% solution polymethacrylic amideare added. After heating for some time a product is obtained which is agoodprecipitant for acid dyes and tanning materials containing acidgroups.

This-solution may be used to fix dyes on cotton, artificial silk orlinen fabrics. The fabric is first treated with the solution and the dyeis then applied at about C. The linen may be dyed with a 0.2% solutionof Diamine pure blue FF (Schulz Farbstolftabellen, vol. 1, No. 510). Theartificial silk may be dyed with a 0.05% solution of Chrome Leatherblack RW extra (Schulz Suppl. vol. 1, page 71). The cotton may be dyedwith a 0.2% solution of the diamine pure blue or with a 0.1% solution ofBenzo dark'green B (Schulz, vol. II, page 32, and Suppl. vol. II, page124). The colors thus obtained are much faster than those obtained withthe same dyes on untreated fabrics.

Example 9 9.7 parts by weight of 35% glycocoll are mixed with 16.6 partsby weight of a 10% solution of polymethacrylic amide. The resultingprecipi tate is redissolved by heating with 4 parts by weight of 30%formaldehyde. The solution is rendered acid with 5.4 parts by weight of96% acetic acid or with the equivalent amount of sulphuric acid, formicacid or phosphoric acid;

The product may be used for fixing tanning materials.

Example 10 2.5 parts by weight of propylamine are mixed with 1.1 partsby weight of 85% formic acid and 2.5 parts by weight of 30% formaldehydeare added. After heating, parts of a aqueous solution of aninterpolymerization product consisting of 80 parts by weightpolymethacrylic amide and parts by weight methylacrylate are addedsuccessively in portions. The unsoluble residue is filtered ofi. Thesolution may be used for precipitating tanning materials from sulfitepulp.

Example 11 5 parts by weight of a 33% ethylamine are mixed with 2 partsbyweight of concentrated sulphuric acid and 3.2 parts by weight of 30%formaldehyde are addedv to this solution while stirring. After heating10 parts by weight of a 10% aqueous solution of an interpolymerizationproduct consisting of 75 parts by weight polymethacrylic amide and partsby. weight ethylmethacrylate are added in portions and the heatingcontinued. The product may be used for the precipitation of tanningmaterial.

Example 12 138 parts by weight of a 42% dimethylamine are heated with 70parts by weight of formaldehyde for 2 to 3 hours under a refluxcondenser until the-liquid which is first cloudy has become absolutelyclear. To this alkaline solution are added while stirring 2130 parts byweight of a 3.3% aqueous solution of polyacrylic nitrile which has beensaponified with 65% of the amount of Example 13 21 parts by weight of adibutylamine are mixed with 14 parts by weight of 85% orthophosphoricacid. To the solution are added 7.5 parts by weight of 30% formaldehyde.After heating, 42.5 parts by weight of a 10% aqueous solution ofpolymethacrylic amide is added in portions and heating is continueduntil'the solution has become absolutely clear.

Example 14 30 parts by weight of 50% cyclohexylamine are mncrled with 21parts by weight of 96% acetic ac1 To this solution are added 7.5 partsby weight of 30% formaldehyde. After heating, 42.5 parts by weight of a10% aqueous solution of polymethacrylic amide is added in portions whilestirring and the heating is continued until the solution becomesabsolutely clear.

Example 15 25.5 parts by weight of 50% piperidine are mixed with 12.5parts by weight of formic acid. To this solution 4.2 parts by weight ofallylaldehyde is added. While heating and stirring, 42.5 parts by weightof a 10% aqueous solution of polymethacrylic amide is added in portionsand the heating is continued until the solution becomes perfectly clear.

Example 16 32 parts by weight of 50% benzylamine and 70 parts of 10%furfurol are mixed and 10 parts of 85% formic acid is added to thesolution. This solution is then heated and stirred and 42.5 parts of a10% aqueous solution of polymethacrylic amide added, the heating beingcontinued until the solution becomes absolutely clear.

Example 17 Chrome-tanned upper leather is neutralized and washed out asusual and then drummed for one hour with 100% of water (calculated onthe shaved weight) and one per cent. of the solution prepared accordingto Example 2.

After this time the leather is dyed in a fresh bath with 1% Acid leatherbrown EG (Schultz Farbstofi-Tabellen, vol. II, page 189) and 100% ofwater at 65 C. After the complete absorption of the dyestufi ,theleather is fatliquored usually in a fresh bath. A particularly full andeven dyeing is obtained.

Example 18 Chrome tanned glove-leather is neutralized, washed out andfatliquored as usual and then drummed for one hour in a fresh bath with100% of water and 2% of the solution prepared according to Example 2.

Then the leather is dried and wet back. It is then drummed with 100% ofwater at 65 C. (calculated on the weight of the wet leather), 0.8%Cotton brown RLVN, 0.8% Cotton brown GNJ (Schultz Farbstofi-Tabellen,vol. II, page 30, 'and Suppl. vol. II, page 123) and 0.5% Acid leatherbrown EGR (Schultz Farbstoif-Tabellen, Suppl. vol. 11, page 240) untilthe dye solution is completely exhausted. The leather is thenfatliquored, set out and dried as usual.

The treatment of the leather causes a complete absorption of the dye.

Example 19 g. of desized rayon staple fiber are drummed with 250 g. ofthe impregnation product prepared according to example 2 and 250 cc.water for 5 minutes and then pressed. It is dried at 30-40 C. and dyedwith a solution containing 1 g. Acid anthracene brown RH extra (SchultzFarbstoff- Tabellen, vol. 1, Nr. 134) to 1 liter water at 90 C., thenwashed and dried.

The resulting color is much fuller than when the impregnation product isomitted.

Example 20 500 g. of desized rayon staple fiber are drummed with 800 g.of the impregnation product prepared according to Example 2.and 800 cc.water for minutes and then pressed. v It is dried at 45-50 C. and dyedwith a solution containing 2 g. Nigrosin WLA (Schultz Farbstoil-Tabellen, vol. I, Nr. 986 and Suppl. vol. II, page y 56) to 1 liter ofwater at 90 C., then washed and dried.

This acid dye cannot be fixed directly on the desized rayon staple fiberbut after impregnation of the fiber with the product described inExample 2, the dye can be permanently fixed.

Subject matter pertaining to the preparation of the condensationproducts of the polymeric amide, an amine and an aldehyde is claimed incopending application Serial No. 291,329 filed August 22, 1939. Subjectmatter pertaining to the use of these condensation products in thetreatment of leather is claimed in copending application Serial No.291,328, filed August 22, 1939, which on June 14, 1940, issued as U. S.Patent No. 2,205,355.

We claim: v

l. The process of dyeing organic fibrous material which comprisestreating said material with a product capable of forming an insolublecompound with an acid dye and whichis prepared by condensing together anon-aromatic amine having at least one hydrogen atom attached to thenitrogen atom thereof, an aldehyde, and a water-soluble polymeric amide,and thereafter dyeing said material with an acid dye.

2. The process of dyeing organic fibrous material which comprisestreating said material with a product capable of forming an insolublecompound with an acid dye and which is prepared by condensing togetheran aliphatic amine having at least one hydrogen atom attached to-thenitrogen atom thereof, an aldehyde, and a water-soluble polymeric amide,and thereafter dyeing said terial whichrcomprises treating said materialwith a product capable of forming an insoluble compound with an acid dyeand which is pre- .aldehyde, and a water-soluble polymeric amide.

pared by condensing together dimethylamine,

formaldehyde, and a water-soluble polymeric amide, and thereafter dyeingsaid material with an acid dye.

5. The process of dyeing organic fibrous mate- 7 rial which comprisestreating said material with a product capable of forming an insoluble001111 pound with an acid dye and which is prepared by condensingtogether dimethylamine, formaldehyde, and a water-solublepolymethacrylic amide,

and thereafter dyeing said material with an acid dye.

The process of dyeing organic fibrous ma- -terial which comprisestreating said material with a product capable of forming an insolublecompound with an acid dye and which is prepared by condensing togetherdimethylamine, formaldehyde, and a water-soluble product containingamido groups and being obtained by the attached to the nitrogen atomthereof, an' aldehyde, and a water-soluble-polymeric amide, andthereafter dyeing said material with an acid dye.

8. The process of dyeing organic fibrous material which comprisestreating said material with a product capable of-forming an insolublecompound with an acid dye and which is prepared by condensing together asecondary aliphatic amine having at' least one hydrogen atom attached tothe nitrogen atom thereof, formaldehyde, and a water-soluble polymericamide, and thereafter dyeing said material with an acid dye.

9. The process of dyeing organic fibrous material which comprisestreating said material with a product capable of forming an insolublecompound with an acid dye and which is prepared by condensing together asecondary aliphatic amine having at least one hydrogen atom attached tothe nitrogen atom thereof, furfurol, and a water-soluble polymericamide, and thereafter dyeing said material with an acid dye.

10. Theprocess-of dyeing organic fibrous material which comprisestreating said material with an acid dye and a product capable of formingan insoluble compound with said dye and which is prepared by condensingtogether a nonaromatic. amine having at least one hydrogen atom attachedto the nitrogen atom thereof, an

o'rro GRIMM.

HANS RAUCH.- y

